The present invention is designed to further improve upon the applicants earlier cable barrier post covered by NZ Patent No. 546969.
The post in NZ 546969 was itself designed to overcome problems with conventional cable barrier posts for a roading network which have a single aperture (slot) extending downwards though the middle of the barrier post as shown in FIG. 7. This slot retaining one or more barrier cables within the cable barrier system.
In short, one of the major drawbacks with this conventional single slot construction is that in order to accommodate multiple cables, the length of the slot is relatively long compared to the length of the post. As a consequence sides of the slot have considerably less strength than the remainder of the post. Accordingly, this necessitates constructing the post in a manner that provides sufficient lateral strength to help prevent shearing or buckling of the post in this weakened region. Thus, typically posts have to have a solid construction, or use stronger materials in their construction, to compensate for the reduction of strength and this understandingly adds to their cost.
Furthermore, the location of the slot within these barrier posts makes it difficult to replace, one or more posts, that may be damaged or broken, within an erected cable barrier system. The cables have to be loosened within the cable barrier system and/or a large post hole relative to the size of the post may have to be dug to allow room for manoeuvring the new post into position, in order to insert the post into the already erected cable barrier.
However, whilst the post of NZ 546969 addressed the aforementioned shortcomings with the single slot post, the Applicant has now found that in practice, the post in NZ 546969 also has a number of shortcomings. One such shortcoming is the folding over of the top of the post, following an impact with the barrier. This ends up trapping at least one of the cables within the aperture and thus reduces the energy that can be absorbed if the cables were free to fully flex.
In addition, it also means the post cannot be re-used which is wasteful and expensive.
It would therefore be useful to have a post which improves upon the post in NZ 546969 as well as addresses the issues with the single slot post discussed earlier.
All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.
It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.
All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.
Throughout this specification, the word “comprise”, or variations thereof such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.